An injected therapeutic typically has a designated injection route that is dependent on such factors as the timescale of the drug action, the dosage frequency, the required absorption rate for intended effect, and the target location(s). In particular, the subcutaneous (SC) space is considered to be useful for a number of applications and indications. When injecting into the SC space, ensuring that the injectate does not pass through the SC layer and into deeper layers is desirable because further penetration may reduce treatment efficacy, cause patient discomfort or pain, and damage internal tissue. There remains a need for needle-free injection guides that mitigate risks of over-penetration or under-penetration during needle-free injection into the subcutaneous space.